The present disclosure relates to a wheel suspension of a motor vehicle. The wheel suspension includes a transverse leaf spring arranged along a transverse axis of a motor vehicle and which transverse leaf spring is connected via two bearings with a body of the vehicle and connected in an articulated manner at its two mutually opposite ends with a stub axle or a suspension arm.
Coiled steel springs are mainly used in car manufacturing for suspending the car body. These steel springs are usually arranged close to the wheel irrespective of the configuration of the axle. In order to reduce rolling motions of the vehicle body, anti-roll bars made of steel are mostly used between the suspension points of an axle. Transverse leaf springs are also used for the suspension of the car body as an alternative to the steel springs, which leaf springs are mostly made of fiber-reinforced materials in their current configuration.
A high rolling spring rate is important for commanding a motor vehicle especially when negotiating curves, which rolling spring rate counteracts excessive rolling motions of the body of the motor vehicle. Another important aspect is the highest possible value of the ratio of the rolling spring rate to the lifting spring rate of a wheel of a motor vehicle, which can only be achieved by the installation of an anti-roll bar in the currently known system for suspending motions of the car body, which has a disadvantageous effect on the weight of the car body suspension system.
The present disclosure relates to a weight-reduced wheel suspension in which the function of the anti-roll bar can be integrated in the transverse leaf spring.
This present disclosure more particularly relates to a wheel suspension of a motor vehicle including a transverse leaf spring arranged along a transverse axis of the motor vehicle and which transverse leaf spring is connected via two bearings with a body of the vehicle and connected in an articulated manner at its two mutually opposite ends with a stub axle or suspension arm. The bearings are arranged such that the transverse leaf spring is stiffly fixed in a direction of a vertical axis of the vehicle and is movable in a translatory manner in a direction of the transverse axis of the vehicle and is rotationally movable around an axis that is parallel to a longitudinal axis of the vehicle.
The bearings are arranged in the wheel suspension in accordance with the present disclosure. As noted above, the suspension system includes a transverse leaf spring which is arranged along a transverse axis of the motor vehicle and which is connected via at least two bearings with a vehicle body and at its respective mutually opposite ends in an articulated manner with a stub axle or suspension arm in such a way that the transverse leaf spring is fixed in a relatively stiff way in the direction of the vertical axis of the vehicle, but is movable at the same time in the direction of the transverse axis of the vehicle in a translatory manner and in a rotationally soft manner around an axis directed parallel to the longitudinal axis of the vehicle. The translatory mobility of the transverse leaf spring in the direction of the transverse axis of the vehicle allows reducing the distance of the transverse leaf spring when deflected.
The transverse leaf spring can be mounted in such a way on the vehicle body by such bearings so that the ratio of a rolling spring rate to a lifting spring rate can be set to such a large value that an installation of an anti-roll bar for stabilizing the vehicle is unnecessary.
Advantageous embodiments, according to the present disclosure, are discussed further herein.
In accordance with an embodiment of the present disclosure, the bearing includes two holders which are fixed to the vehicle body and are filled with an elastic material. The embodiment also includes a guide part which encases the transverse leaf spring and which is rotatably held on the holders about an axis directed approximately parallel to the longitudinal axis of the vehicle by bolts extending in the direction of the longitudinal axis of the vehicle out of the guide part. The bolts are movably mounted in the holders in a plane perpendicularly to the vertical axis of the vehicle.
The rotating ability of the bearing outside of the transverse leaf spring is realized thereby. The bearing is fixed to the vehicle body in such a way that the transverse leaf spring is capable of rotating with the bearing around an axis directed parallel to the longitudinal axis of the vehicle, depending on the rolling motion of the vehicle body and still ensuring a vertical fixing of the transverse leaf spring.
According to an embodiment of the present disclosure, the bearing includes two clamping parts which encase the transverse leaf spring and are enclosed at least in part by an elastic material. One of the clamping parts is arranged between the vehicle body and the transverse leaf spring and the other clamping part is located between the transverse leaf spring and a bracket engaging around the transverse leaf spring and the clamping parts on three sides and is fixable to the vehicle body. The transverse leaf spring may also be mounted with a bearing arranged in such a way that it has freedoms of mobility in the bearing as noted above.
In accordance with an embodiment of the present disclosure, one of the two clamping parts includes two metal or plastic plates which are encased with the elastic material and are disposed parallel with respect to each other and to the broadside of the transverse leaf spring. One of the metal or plastic plates is provided with a deflection or bulging which is convex centrally to the other metal or plastic plates in the direction of the longitudinal axis of the transverse leaf spring. The metal or plastic plates arranged in this manner ensure a roll-off kind of behavior of the transverse leaf spring when the transverse leaf spring is deflected, on the one hand, and this surface pressing is reduced to a level permissible for the transverse leaf spring on the other hand.
An elliptical solid core is embedded, according to an embodiment of the present disclosure, between the plastic or metal plates, which solid core is encased with the elastic material and with which the rotational movement of the transverse leaf spring around the axis directed parallel to the longitudinal axis of the vehicle is enabled. Moreover, a displacement of the transverse leaf spring in the direction of its longitudinal axis is facilitated by this configuration because two further sliding planes may be introduced into the bearing by the solid core.
In accordance with an embodiment of the present disclosure, the bearing is actively rotationally movable around an axis directed parallel to the longitudinal axis of the vehicle. This can occur, for example, in form of an electromotive triggering of the bearing, thereby enabling an active control of the car body suspension.
Other aspects of the present disclosure will become apparent from the following descriptions when considered in conjunction with the accompanying drawings.